Although rare, it is possible that people who have recovered from Covid-19 could be re-infected, a recent study from Hong Kong suggests, the World Health Organization said on Wednesday.
On Monday, the researchers published a study that found the first documented case of Covid-19 reinfection in a 33-year-old man. According to STAT News, the man was not infected until the end of March and then again about 4½ months later.
"That doesn't mean a lot is happening. We know it is possible," said Maria Van Kerkhove, WHO director of Emerging Diseases and Zoonosis, during a live Q&A session. "It's something we knew might be possible based on our experience with other human coronaviruses."
While much unknown is known about SARS-CoV-2, the virus that causes Covid-19, researchers know that infected people develop some antibody response against the disease after they recover. However, researchers don't yet know how long this immunity will last, Van Kerkhove said.
The Hong Kong case is also not believed to be the only time anyone has been infected with the coronavirus twice, although it is the first documented case, she added.
"This is an example of 23.5 million cases, but we expect infected people to develop an antibody response, they develop an immune response that lasts for some time, so we're learning," she said.
Van Kerkhove reiterated that someone infected or not should continue to follow suggested social distancing guidelines, wear face covers, and follow other recommended health precautions.
"Yes, it is possible that we will see a new infection, but you know we have the tools to keep people from becoming infected," said Van Kerkhove.
The study also doesn't change the progress made towards a coronavirus vaccine, added Van Kerkhove. More knowledge about how the body reacts to a potential vaccine is being discovered through ongoing clinical trials, she said.
“People think, 'Oh, that means a vaccine isn't working.' That doesn't mean that,” she said. "We are still developing vaccines and this is where incredible progress is being made."